Photoacoustic-enabled automatic vascular navigation: accurate and naked-eye real-time visualization of deep-seated vessels

Accurate localization of blood vessels with image navigation is a key element in vascular-related medical research and vascular surgery. However, current vascular navigation techniques cannot provide naked-eye visualization of deep vascular information noninvasively and with high resolution, resulting in inaccurate vascular anatomy and diminished surgical success rates. Here, we introduce a photoacoustic-enabled automatic vascular navigation method combining photoacoustic computed tomography with augmented and mixed reality, for the first time, to our knowledge, enabling accurate and noninvasive visualization of the deep microvascular network within the tissues in real time on a real surgical surface. This approach achieves precise vascular localization accuracy (<0.89 mm) and tiny vascular relocation latency (<1 s) through a zero-mean normalization idea-based visual tracking algorithm and a curved surface-fitting algorithm. Further, the subcutaneous vessels of minimum diameter (∼0.15 mm) in rabbit thigh and the maximum depth (∼7 mm) in human arm can be vividly projected on the skin surface with a computer vision-based projection tracking system to simulate preoperative and intraoperative vascular localization. Thereby, this strategy provides a way to visualize deep vessels without damage on the surgical surface and with precise image navigation, opening an avenue for the application of photoacoustic imaging in surgical operations.